Poly elastic modulus

Fig. 14. Amplitude dependences (y0 is the amplitude of cyclic deformations) of the elastic modulus for frequency a) = 63 s 1 13% dispersion of acetylene carbon black in low- (/) and high-molecular (2) poly(isobutylene)s...

Fig. 1.9. Dependence of elastic modulus on temperature in amorphous (—) and in crystalline (—) poly(ethylene terephthalate)...

Figure 5.18 Cross-linking profile of poly-CA using the triazine-based cross-linking agent. Filled symbols denote the elastic modulus (G ) whereas empty symbols denote the loss modulus (G") at a strain value of 0.1. The percentage of the triazine-based cross-linking agent is based on the cyanuric acid groups attached to the polymer.

FIGURE 10.23 The distance dependence of the steric interaction energy of latex particles stabilized by poly(vinyl alcohol) in water (1) 500 nm, (2) 100 nm, and (3) 10 nm. The elastic modulus is 1.4 x 10 nm . Data from Sonntag [45]. 

The properties of tridimensional network formed in the poly(vinyl butyral) on irradiation were estimated by means of ultrasonic and thermal methods. It was found, for instance, that the elastic modulus changed over from 3.33x10 dynes cm. 2 to 4.03x10 dynes cm"2 for gel content increase from 0.082 up to 0.923. Simultaneously, the thermal stability of the crosslin-ked polymer rised from 167°C up to 417°C. [ 2]... 

The chemical and mechanical stability of poly(n-butyl acrylate)(PnBA) to weathering, especially to solar radiation, is of interest for possible use of this material as an encapsulant/ pottant for silicon cell solar energy arrays. This application requires that the material retain an acceptable level of its desirable properties, such as transparency, elastic modulus, etc., over several years of exposure to intermittent moisture, temperatures ranging from -10 to 50 C, solar radiation, and other norms and extremes of exposure conditions. Knowledge of the dependence of changes in properties and composition of the material on exposure conditions is a requisite for establishing reasonable estimates of its prospective performance lifetime characteristics. 

Another example of network formation is found in PEO (poly(ethylene oxide))-silica systems [58, 59]. At relatively small-particle concentrations, the elastic modulus increases at low frequencies, suggesting that stress relaxation of these hybrids is effectively arrested by the presence of silica nanoparticles. This is indicative of a transition from liquidlike to solidlike behavior. At high frequencies, the effect of particles is weak, indicating that the influence of particles on stress relaxation dynamics is much stronger than their influence on the plateau modulus. 

Polymers such as EVA, are used as admixture because it modify the elastic modulus, toughness, permeability and bond strength to various substrates in cement and mortars [10]. The polymer forms a film that creates a network inside the cement matrix, partially covering hydrated and anhydrous cement particles, sealing pores and bridging microcracks. Besides, this addition also changes the hydration rate. Silva et al [11] compare the effects of two polymers a water soluble polymer (HPMC — hydroxypropylmethylcellulose) and a latex [EVA-poly(ethylene-co-vinyl acetate)] on... 

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